Door latch mechanism



Jan. 23, 1940.

F. KAISER DOOR LATCH MECHANISM Filed July 11, 1939 2 Sheets-Sheet 1 K INVENTOR.

.21" ea? azls'ez" BY Mk1 \Z/7fl ATTORNEY.

Jan. 23, 1940. KAISER 2,188,149

DOOR LATCH MECHANISM Filed July 11, 1939 2 Sheets-Sheet 2 Hr I II /5' 5.? /m'f J6 W Z6 1 #7? @070 ATTORNEY.

Patented Jan. 23, 1940 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to improvements in door latch mechanism, and the invention has reference, more particularly, to a novel door latch mechanism including means, operative from one side of the door served thereby, for locking the latch mechanism against manipulation from the opposite side of said door.

The invention has for an object to provide a novel improved latch mechanism of the kind which is contained within a tubular-or cylindrical casing mortised into a door body; said latch mechanism being selectively manipulatable by the spindle means of interior and exterior knobs which are disposed respectively at the inner and outer sides of the door served by the latch mechanism.

The invention has for another object to provide in a door latch mechanism novel means, operative from the interior side of the door served by the latch mechanism, for locking the exterior door knob spindle against operation, whereby the door, under such circumstances cannot be opened by manipulation of the exterior door knob; said locking means including releasing means operative by turning the interior door knob spindle so as to automatically release the exterior door knob spindle subject to latch manipulation thereby after the door has again been opened from the inside.

The invention has for another object to provide a locking means of the kind above mentioned which is subject to release from the outside of the door by means of an insertable key.

The invention has for still another object to provide improvements in the latching mechanism per se, whereby the various movable parts thereof are so spring balanced and controlled that operation thereof by the knob spindle means is smoothly and easily attained with a minimum of resistance, and whereby the latch mechanism is more efficiently yieldably supported in latching position, as well as quickly returned to latching position after releasing manipulation.

Other objects of this invention, not at this time more particularly enumerated, will be understood from the following detailed description of the same.

An illustrative embodiment of the invention is shown in the accompanying drawings, in which:

Fig. 1 is a fragmentary inside face view of a door equipped with the novel latch mechanism of this invention; Fig. 2 is a vertical cross section, taken on line 2-2 in Fig. 1, the locking means being shown in released position; Fig. 3 is a view similar to that of Fig. 2, but with the locking means shown in locking position; Fig. 4 is a transverse sectional view, taken on line 4-4 in Fig. 3, but drawn on an enlarged scale; Fig. 5 is a view similar to that of Fig. 4, but showing the locking means as released by the turning of the interior knob spindle; Fig. 6 is a longitudinal section taken on line 6-6 in Fig. 2, but drawn on an enlarged scale, and showing the normal projected position of the door latch; and Fig. 7 is a view similar to that of Fig. 6, but showing the door latch retracted.

Similar characters of reference are employed in the above described views, to indicate corresponding parts.

Referring to the drawings, the reference char acter l0 indicates a door to be served by the novel latch mechanism. Mounted in a mortised opening ll, extending inwardly into the door body from its free end, is a cylindrical casing. This casing is longitudinally divided into two half sections l2 and I3 which are suitably secured together, one of which, as e. g. the section 12, is provided with an anchoring plate or flange portion l4, adapted to be countersunk in thedoor body edge and secured thereto by screws (not shown) in the usual manner, thus retaining the casing in operative assembled relation to said door body. Said anchoring plate or flange portion I4 is provided with an opening l5 aligned with the interior of the casing, and through which the chamfered latch nosing I6 of the latch mechanism is normally outwardly projected. Said latch nosing i6 is carried by a latch plate H, which is suitably slidably supported in the forward interior portion of the casing. Said latch plate I! is formed with laterally spaced rearwardly directed longitudinal legs 3 which straddle a stationary abutment member l9, which is preferably formed as an integral part of the casing section 12. Extending rearwardly from one of the latch plate legs I8 is a tail-piece having at its extremity an upstanding retractor lug 2|. Said latch plate I1 is yieldably urged forwardly to latch nosing projecting position by a compression spring 22 engaged between the same and said abutment member I9; said latch plate having a keeper lug 23 for seating the end of the spring 22 which engages the same.

The casing sections l2-l3 are providedwith laterally aligned transverse bearing portions 24 in which are respectively journaled the opposite ends of the journal hub 25 of a rotary cam piece which provides oppositely and radially extending cam arms 28.

Longitudinally slidable in the rearward interior portion of the casing is a pull-plate 21 having rearwardly extending laterally spaced legs 28 adapted to straddle said hub 25 of the cam piece. Said legs 28 are each provided, adjacent their extremities, with ofliset retractor lugs 29 respectively engageable by the respective cam arms 26 of said cam piece. At its forward end, said pull-plate 21 is provided with a longitudinally extending oifse't pull-tongue 30. This pulltongue is provided, adjacent to its free end, with an upstanding thrust lug 3|. The interior of the casing section I2 is suitably formed to provide a guiding slideway 32, for said pull-tongue 30. Pivotally mounted on a suitably located fulcrum stud 33, with which said casing section I2 is provided, is a transversely disposed latch plate actuating lever 34 having a thrust nosing 35 at its free end to operatively engage the retractor lug 2| of the latch plate tail-piece 20; said lever being operatively engaged, at a point intermediate its fulcrum and free end, by said pull-plate thrust lug 3|, whereby a minimum actuating movement of said pull-plate is compounded by and transmitted through said lever 34 to efiect a maximum latch plate movement adequate to fully retract the latch-nosing l6 when the latch mechanism is actuated.

The pull-plate 21 is yieldably maintained in forwardly moved normal initial position by means of a pair of compression springs 36, which are purchased against the rearward end wall of the casing, with their forward ends engaged respectively with the ends of the respective legs 28 of said pull-plate 21; the latter parts having seating bosses 31 to engage and hold said springs in operative relation thereto. By reason of the provision of said springs 36 to directly thrust upon and forwardly move said pull-plate 21, a yieldable forwardly thrusting force auxiliary to that exercised by the latch-plate spring 22 is furnished, whereby not only is a better balancing of the combined action of the moving parts of the latch mechanism attained, but the use of a less stiff and more smoothly operating latch plate spring is possible, and consequently a smoother and easier action of the latch mechanism as a whole is obtained.

The means for manipulating the above described latch mechanism comprises, a knob spindle means to extend transversely through the rotatable cam piece from one side of the door to the other. Said spindle means comprises an exterior knob spindle 38, preferably of polygonal cross sectional shape, adapted to extend from the exterior side of the door Ill entirely through a correspondingly shaped axial opening 39 with which the hub 25 of the cam piece is provided. Suitably aflixed to the exterior face of the door I0 is an exterior bearing plate 40 through which the outer end portion of said exterior knob spindle 38 extends. Suitably assembled with said bearing plate 40 is a rosette 4|. The outer end portion of said exterior knob spindle 38 is screwthreaded, and screwed onto the same is the exterior knob 42.

Suitably affixed to the interior face of the door I8 is an interior bearing plate 43, having at its outer side a housing chamber 44. Provided in said interior bearing plate 43 is a central bearing portion 45. Affixed to the inner end portion of said exterior knob spindle 38 is a clutch piece 46 adapted to be journaled in the central bearing portion 45 of said bearing plate 43. Formed in the outer end of said clutchplece 46 is an outwardly open central socket 41 'the wall of which is cut away at its upper side -so as to provide, at opposite points in its circumference, upwardly presented clutch shoulders 48. Formed integrally with said clutch piece, so as to extend downwardly from the underside thereof, and within the housing chamber 44 of said interior bearing plate 43, is a radial lock tongue 49.

Cooperative with said exterior knob spindle 38 is an interior knob spindle 50. Aflixed to the inner end of said interior knob spindle 50 is a hub portion 5| of a clutch piece 52. Said clutch piece is provided at opposite sides thereof with clutch shoulders 53 which, as normally disposed, are respectively opposed to the clutch shoulders 48 of said exterior knob spindle clutch piece 46 in such normal spaced relation thereto as to permit of a preliminary free rotataive movement of said clutch piece 52 prior to effective clutching engagement thereof with said clutch piece 46 for purposes presently to be set forth.

Assembled in connection with said interior bearing plate 43 is a chambered cover plate 54 having a central opening 55 in which is journaled a diametrically reduced outward extension 56 of said clutch piece hub portion 5|. Said cover plate defines the outer boundary of the housing chamber 44. Suitably assembled with said cover plate 54 and interior bearing plate 43 is a rosette 51. The outer end portion of said interior knob spindle 50 is screw-threaded, and screwed onto the same is the interior knob 58.

Slidably mounted in guide means 59 provided in connection with the bearing plate 43, and, if desired, also with the bearing plate 40, is a slide member 60 adapted to extend transversely through the body of the door Ill. At its inner end said slide member 60 is provided with a push button 6|, the free end of which projects exteriorly through and beyond the rosette 51. Afiixed to said slide member 60, preferably as an integral part thereof, is a lock plate 62 having a female locking notch 63 for cooperation with the lock tongue of said exterior knob spindle clutch piece 46. Said lock plate is of arcuate formation providing oppositely extending arms or horns 64 having at their extremities undercut internal chamfered cam portions 65. Said slide member 60, and the lock plate 62 carried thereby, is retained against rotative displacement by a suitable feather piece 66 which engages in a spline groove 61 with which a guide means 59 is provided. A spring means 68 is provided to bear upon said slide member 60 with sufficient friction to hold the same against accidental displacement from any given position to which it has been moved.

Connected with said interior knob spindle clutch piece'52, by an upwardly extending radial arm or neck 69 is an arcuate cam plate 16 having oppositely extending arms 1| provided at their extremities with external chamfered cam portions 12 adapted to cooperate at proper times with the internal chamfered cam portions of said lock plate arms or horns 64.

The meeting faces of said cam plate 69 and said interior bearing plate 43 are provided with matching arcuate channels which define a receiving space 13 for a balancing compression spring 14 operative to yieldably hold said cam plate 10, clutch piece 52 and interior knob spindle 50 in normal initial centered positions.

Normally the slide member 60 and its push button 6| are disposed in an outwardly slid position, with the latter projecting from the rosette n beneath the interior knob 68, whereby the lock plate 62 is disposed within the housing chamber 44 an outwardly oifset plane relative to said -cam plate Ill, and so as to withdraw the locking notch 63 from embracing relation to the locktongue 49, thus freeing the exterior knob spindle 33 and clutch piece 46 for manipulative rotation when the exterior knob 42 is. turned and the door is thus opened from outside thereof.

When the lock plate 62 is in the released position above described, the door latch may be actuated from outside the door by turning the exterior knob 42 or from inside the door by turning the interior knob 56. Owing to the clutched interconnection of the exterior and interior spindles 33 and 50, manipulation of either of said knobs will rotate the spindle 38 and thus the cam-piece -26. The turning of said campiece will engage one or the other of its cam arms 26 (as the case may be) with a corresponding retractor lug 29 of the "pull-plate 21, whereby the latter is retracted against the thrust of the springs 36. The rearward movement of said lock-plate 21 moves the thrust lug 3| against the lever 34, thereby swinging the latter rearward so as to produce, through the engagement of the lever nosing with the retractor lug 2| of the latch plate H, a relatively greater rearward sliding movement of said latch plate, whereby the latch nose is retracted to door releasing position.

If it is desired to lock the door against'being opened from the outside, after the door is closed from the inside, the operator merely pushes inwardly upon the push-button 6|, thus sliding inward the slide member and thereby carrying inward the lock plate 62 so that it lies in the plane of the cam-plate ill, in which position the locking notch 63 is disposed to embrace the lock tongue 49 of the exterior knob spindle clutch piece, and consequently said exterior spindle and its knob is locked against operative manipulation. When the lock plate 62 is thus aligned in the plane of the cam-plate 10, the cam portions of the former are opposed to the cam portions 12 of the latter. As a consequence of such relative disposition of these parts, should the interior knob 58 be thereafter turned to reopen the door from the inside, the initial rotative movement of the interior spindle 50 and clutch-piece 52 permits free rotation of these parts relative to the locked exterior spindle clutch piece 46, since their movement is not transmitted to the latter until the normal gap between their clutch shoulders 53 and 46, on one side or the other, is closed. Owing to this free initial rotative movement of the clutch-piece 52, the cam-plate 10 carried thereby partakes of such initial movement, and consequently one or the other of its cam portions 12 (as the case may be) is thrust against the corresponding cam portion 65 of the lock plate 62, whereby the latter is pushed outwardly and back to normal released position so as to carry its locking notch 63 out of embracing relation to the lock tongue 49, thereby freeing the clutch-piece 46 and exterior 'spindle 33 for operative rotative movement, as

thereafter transmitted thereto by continued and completed rotative latch mechanism actuating movement of the interior knob spindle 38. It

will thus be obvious that the exterior knob spindle locking means is automatically released and returned to normal position merely by opening the door from the inside.

Since circumstances might occur under which it would be desirable or necessary to release the lock plate 62 from the exterior side of the door, means are provided for attaining such operation thereof. This means comprises the provision in connection with the exterior rosette 4| of a keyreceiving barrel 15 or other suitable key or like instrumentality admission means. Said key barrel I5 is aligned in opposition to the outwardly directed extremity of the lock plate slide member 60, which, when slid to locking position, is disposed adjacent to the interior end of said key barrel I5. If, when the slide member 60 is thus disposed, a proper key or like instrumentality is inserted through the key barrel l5, and thrust inwardly against the opposed end of said slide member 60, thelatter may be pushed back therewith, so as to move the lock plate 62 back to normal initial released position, whereupon the exterior knob spindle 33 is freed to permit opening of the door from the outside.

I am aware that many changes could be made in the above described latch mechanism, as well as in the details of the construction thereof, without departing from the scope of my invention as defined by the following claims, consequently, I do not limit the invention to the exact arrangement and construction of the devices and parts as set forth in the foregoing specification, nor do I confine myself to' the exact details of the construction of said parts as illustrated in the accompanying drawings.

I claim:

1. A door latchmechanism comprising, a casing, a latch bolt and actuating means therefor housed bysaid casing, an exterior knob spindle operatively engaged with said latch bolt actuating means, aninterior knob spindle, cooperative clutch elements on said spindles whereby rotative movement of the interior spindle is transmitted to said exterior spindle, a movable lock means opear'tive to lock said exterior spindle against rotation, a cam plate actuated by rotary movement of said interior spindle, said cam plate when moved by said interior spindle being operative to move said lock means from looking to released position, and said clutch elements being arranged to permit an initial free rotative movement of said interior spindle and accompanying movement of said cam plate with releasing effect upon said lock means prior to transmission of motion to said exterior spindle.

2. A door latch mechanism comprising, a casing, a latch bolt and actuating means therefor housed by said casing, an exterior knob spindle operatively engaged with said latch bolt actuating means, an interior knob spindle, cooperative clutch elements on said spindles whereby rotative movement of the interior spindle is transmitted to the exterior spindle, said clutch element on said exterior spindle having a radial lock tongue, a movable lock plate having a looking n'otch to embrace said lock tongue, manipulatable means accessible from the inner side of the door served by the latch mechanism for moving said lock plate from normal released position into locking relation to said lock tongue,

a cam plate actuated by rotary movement of. said interior spindle, said cam plate when rotated being operative to move said lock plate from looking position back to normal released position, and said clutch elements being arranged to permit an initial free rotative movement of said interior spindle and said cam plate prior to transmission of motion to said exterior spindle.

3. A door latch mechanism comprising, a casi g, a latch bolt and actuating means" therefor h used by said casing, an exterior knobspindle operatively engaged with said latch bolt actuating means, an interior knob spindle aligned with said exterior spindle, cooperative clutch elements on said spindles whereby rotative movement of the interior spindle. is transmitted to the exterior spindle and latch -bolt actuating means, said clutch element on said exterior spindle having a radial lock tongue, a slide member parallel to said spindles, said slide member having a manipulating push button to project exteriorly of the inner side of a door served by the latch mechanism, a lockplate carried by said slide member, said lock plate having a locking notch to embrace said lock tongue, a cam plate carried by the clutchelement of said interiorspindle, said cam plate when rotated being operative to move said lock plate together with said slide member and push button from operative locking positions back to normal releasedpositions, and said clutch elements being arranged to-permit an initial free rotative'move ment of said interior spindle and its clutch element and cam plate prior to transmission of motion to said exterior spindle.

4. In a door latch mechanism as defined in claim 3, means for applying frictional resistance to said lock plate supporting slide member to yieldably retain the same and said lock plate against accidental displacement from given positions to which the same are moved.

5. A door latch mechanism comprising, 2. casing, a latch bolt and actuating means therefor housed by said casing, an exterior knob spindle operatively engaged with said latch bolt actuating means, an interior knob spindle aligned with said interior spindle and operative to move said lock means from locking to released position prior to transmission of interior spindle movement to said exterior spindle, and means operative from the inside of a door served by said latch mechanism for manually setting said lock means in locking position.

6. A door latch mechanism comprising, a casing, a latch bolt and actuating means therefor housed by said casing, an exterior knob spindle operatively engaged with said latch bolt actuating means, an interior knob spindle aligned with said exterior spindle, cooperative clutch elements joining said spindles, said clutch elements having normally spaced apart cooperating clutch shoulders on diametrically opposite sides thereof whereby an initial rotative movement of said interior spindle in-one direction or the other precedes transmission of its continued movement to said exterior spindle, a movable lock means operative to lock said exterior spindle against manipulation, a rotative cam plate actuated by said interior spindle and operative to move said lock means from looking to released position prior to transmission of interior spindle movement to said exterior spindle, means operative from the inside of a door served by said latch mechanism for manually setting said lock means in lo'cklng position, and key receiving means at theoutside of said door whereby a key inserted therein maybe utilized to return said lock means from looking to released position.

'7. A door latch mechanism comprising, a casing, a latch' boltand'actuating means therefor housed by said casing, an exterior knob spindlev operatively engaged with said latch bolt actuating means, an interior knob spindle aligned with said exterior spindle, cooperative clutch elements joining said spindles, said clutch elements having normally spaced apart cooperating clutch shoulders on diametrically, opposite sides thereof whereby :an' initial rotative movement of said .interiorspindle in one direction or the' 'other precedes transmission of its continued move ment to said exterior spindle, a lock plate having oppositely extending arms eac h terminating in cam portions, means to support said lock plate for bodily movement to and from its looking position, said lock plate and exterior spindle having cooperative interchangeable locking means, a rotative cam plate actuated by said interior spindle, said cam plate having oppositely extending arms terminating in cam portions to cooperate with said lock plate cam por-- tions, and said lock plate supporting means having a manipulating push button exteriorly projecting from the inner side of a door served by said latch mechanism.

8. A door latch mechanism comprising, a casing, a latch bolt and actuating means therefor housed by said casing; an exterior knob spindle operatively engaged with said latch bolt actuating-means, an interior knob spindle aligned with said exterior spindle, cooperative clutch elements joining said spindles, said clutch eleme nts having normally spaced apart cooperating clutch shoulders on diametrically opposite sides thereof .wherebyan initial rotative movement of said interior spindle in one direction or the other precedes transmission of its continued movement to said exterior spindle, a lock plate having oppositely extending arms each terminating in cam portions, means to support said -lock plate forbodily movement to and from its locking position, said lock plate and exterior spindle having cooperative interchangeable locking'means, a rotative cam plate actuated by said interior spindle, said cam plate having oppositely extending arms terminating in cam portions to cooperate with said lock plate cam portions, said lock plate supporting means having a manipulating 0 push button exteriorly projecting from the inner side of a door served by said latch mechanism, and key receiving means at the outside of said door whereby a key inserted therein may be utilized to engage and move said lock plate supporting means so as to carry said lock plate from locking back to released position.

FRED KAISER. 

